BMC/Intel-BMC/linux.git/arch/powerpc, branch dev-5.2

KVM: PPC: Book3S: Fix incorrect guest-to-user-translation error handling

2019-09-06T08:23:41+00:00

commit ddfd151f3def9258397fcde7a372205a2d661903 upstream. H_PUT_TCE_INDIRECT handlers receive a page with up to 512 TCEs from a guest. Although we verify correctness of TCEs before we do anything with the existing tables, there is a small window when a check in kvmppc_tce_validate might pass and right after that the guest alters the page of TCEs, causing an early exit from the handler and leaving srcu_read_lock(&vcpu->kvm->srcu) (virtual mode) or lock_rmap(rmap) (real mode) locked. This fixes the bug by jumping to the common exit code with an appropriate unlock. Cc: stable@vger.kernel.org # v4.11+ Fixes: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO") Signed-off-by: Alexey Kardashevskiy Signed-off-by: Paul Mackerras Signed-off-by: Greg Kroah-Hartman

powerpc: Allow flush_(inval_)dcache_range to work across ranges >4GB

2019-08-29T06:30:27+00:00

The upstream commit: 22e9c88d486a ("powerpc/64: reuse PPC32 static inline flush_dcache_range()") has a similar effect, but since it is a rewrite of the assembler to C, is too invasive for stable. This patch is a minimal fix to address the issue in assembler. This patch applies cleanly to v5.2, v4.19 & v4.14. When calling flush_(inval_)dcache_range with a size >4GB, we were masking off the upper 32 bits, so we would incorrectly flush a range smaller than intended. This patch replaces the 32 bit shifts with 64 bit ones, so that the full size is accounted for. Signed-off-by: Alastair D'Silva Acked-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/nvdimm: Pick nearby online node if the device node is not online

2019-08-25T14:10:29+00:00

[ Upstream commit da1115fdbd6e86c62185cdd2b4bf7add39f2f82b ] Currently, nvdimm subsystem expects the device numa node for SCM device to be an online node. It also doesn't try to bring the device numa node online. Hence if we use a non-online numa node as device node we hit crashes like below. This is because we try to access uninitialized NODE_DATA in different code paths. cpu 0x0: Vector: 300 (Data Access) at [c0000000fac53170] pc: c0000000004bbc50: ___slab_alloc+0x120/0xca0 lr: c0000000004bc834: __slab_alloc+0x64/0xc0 sp: c0000000fac53400 msr: 8000000002009033 dar: 73e8 dsisr: 80000 current = 0xc0000000fabb6d80 paca = 0xc000000003870000 irqmask: 0x03 irq_happened: 0x01 pid = 7, comm = kworker/u16:0 Linux version 5.2.0-06234-g76bd729b2644 (kvaneesh@ltc-boston123) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #135 SMP Thu Jul 11 05:36:30 CDT 2019 enter ? for help [link register ] c0000000004bc834 __slab_alloc+0x64/0xc0 [c0000000fac53400] c0000000fac53480 (unreliable) [c0000000fac53500] c0000000004bc818 __slab_alloc+0x48/0xc0 [c0000000fac53560] c0000000004c30a0 __kmalloc_node_track_caller+0x3c0/0x6b0 [c0000000fac535d0] c000000000cfafe4 devm_kmalloc+0x74/0xc0 [c0000000fac53600] c000000000d69434 nd_region_activate+0x144/0x560 [c0000000fac536d0] c000000000d6b19c nd_region_probe+0x17c/0x370 [c0000000fac537b0] c000000000d6349c nvdimm_bus_probe+0x10c/0x230 [c0000000fac53840] c000000000cf3cc4 really_probe+0x254/0x4e0 [c0000000fac538d0] c000000000cf429c driver_probe_device+0x16c/0x1e0 [c0000000fac53950] c000000000cf0b44 bus_for_each_drv+0x94/0x130 [c0000000fac539b0] c000000000cf392c __device_attach+0xdc/0x200 [c0000000fac53a50] c000000000cf231c bus_probe_device+0x4c/0xf0 [c0000000fac53a90] c000000000ced268 device_add+0x528/0x810 [c0000000fac53b60] c000000000d62a58 nd_async_device_register+0x28/0xa0 [c0000000fac53bd0] c0000000001ccb8c async_run_entry_fn+0xcc/0x1f0 [c0000000fac53c50] c0000000001bcd9c process_one_work+0x46c/0x860 [c0000000fac53d20] c0000000001bd4f4 worker_thread+0x364/0x5f0 [c0000000fac53db0] c0000000001c7260 kthread+0x1b0/0x1c0 [c0000000fac53e20] c00000000000b954 ret_from_kernel_thread+0x5c/0x68 The patch tries to fix this by picking the nearest online node as the SCM node. This does have a problem of us losing the information that SCM node is equidistant from two other online nodes. If applications need to understand these fine-grained details we should express then like x86 does via /sys/devices/system/node/nodeX/accessY/initiators/ With the patch we get # numactl -H available: 2 nodes (0-1) node 0 cpus: node 0 size: 0 MB node 0 free: 0 MB node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 node 1 size: 130865 MB node 1 free: 129130 MB node distances: node 0 1 0: 10 20 1: 20 10 # cat /sys/bus/nd/devices/region0/numa_node 0 # dmesg | grep papr_scm [ 91.332305] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Region registered with target node 2 and online node 0 Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190729095128.23707-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin

KVM: Fix leak vCPU's VMCS value into other pCPU

2019-08-16T08:11:11+00:00

commit 17e433b54393a6269acbcb792da97791fe1592d8 upstream. After commit d73eb57b80b (KVM: Boost vCPUs that are delivering interrupts), a five years old bug is exposed. Running ebizzy benchmark in three 80 vCPUs VMs on one 80 pCPUs Skylake server, a lot of rcu_sched stall warning splatting in the VMs after stress testing: INFO: rcu_sched detected stalls on CPUs/tasks: { 4 41 57 62 77} (detected by 15, t=60004 jiffies, g=899, c=898, q=15073) Call Trace: flush_tlb_mm_range+0x68/0x140 tlb_flush_mmu.part.75+0x37/0xe0 tlb_finish_mmu+0x55/0x60 zap_page_range+0x142/0x190 SyS_madvise+0x3cd/0x9c0 system_call_fastpath+0x1c/0x21 swait_active() sustains to be true before finish_swait() is called in kvm_vcpu_block(), voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin() loop greatly increases the probability condition kvm_arch_vcpu_runnable(vcpu) is checked and can be true, when APICv is enabled the yield-candidate vCPU's VMCS RVI field leaks(by vmx_sync_pir_to_irr()) into spinning-on-a-taken-lock vCPU's current VMCS. This patch fixes it by checking conservatively a subset of events. Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Christian Borntraeger Cc: Marc Zyngier Cc: stable@vger.kernel.org Fixes: 98f4a1467 (KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop) Signed-off-by: Wanpeng Li Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails

2019-08-16T08:11:03+00:00

[ Upstream commit 3a855b7ac7d5021674aa3e1cc9d3bfd6b604e9c0 ] In some cases initial bind of scm memory for an lpar can fail if previously it wasn't released using a scm-unbind hcall. This situation can arise due to panic of the previous kernel or forced lpar fadump. In such cases the H_SCM_BIND_MEM return a H_OVERLAP error. To mitigate such cases the patch updates papr_scm_probe() to force a call to drc_pmem_unbind() in case the initial bind of scm memory fails with EBUSY error. In case scm-bind operation again fails after the forced scm-unbind then we follow the existing error path. We also update drc_pmem_bind() to handle the H_OVERLAP error returned by phyp and indicate it as a EBUSY error back to the caller. Suggested-by: "Oliver O'Halloran" Signed-off-by: Vaibhav Jain Reviewed-by: Oliver O'Halloran Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190629160610.23402-4-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin

powerpc: fix off by one in max_zone_pfn initialization for ZONE_DMA

2019-08-16T08:10:58+00:00

[ Upstream commit 03800e0526ee25ed7c843ca1e57b69ac2a5af642 ] 25078dc1f74be16b858e914f52cc8f4d03c2271a first introduced an off by one error in the ZONE_DMA initialization of PPC_BOOK3E_64=y and since 9739ab7eda459f0669ec9807e0d9be5020bab88c the off by one applies to PPC32=y too. This simply corrects the off by one and should resolve crashes like below: [ 65.179101] page 0x7fff outside node 0 zone DMA [ 0x0 - 0x7fff ] Unfortunately in various MM places "max" means a non inclusive end of range. free_area_init_nodes max_zone_pfn parameter is one case and MAX_ORDER is another one (unrelated) that comes by memory. Reported-by: Zorro Lang Fixes: 25078dc1f74b ("powerpc: use mm zones more sensibly") Fixes: 9739ab7eda45 ("powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac") Signed-off-by: Andrea Arcangeli Reviewed-by: Christoph Hellwig Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190625141727.2883-1-aarcange@redhat.com Signed-off-by: Sasha Levin

powerpc/kasan: fix early boot failure on PPC32

2019-08-06T17:08:17+00:00

commit d7e23b887f67178c4f840781be7a6aa6aeb52ab1 upstream. Due to commit 4a6d8cf90017 ("powerpc/mm: don't use pte_alloc_kernel() until slab is available on PPC32"), pte_alloc_kernel() cannot be used during early KASAN init. Fix it by using memblock_alloc() instead. Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") Cc: stable@vger.kernel.org # v5.2+ Reported-by: Erhard F. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/da89670093651437f27d2975224712e0a130b055.1564552796.git.christophe.leroy@c-s.fr Signed-off-by: Greg Kroah-Hartman

powerpc/pmu: Set pmcregs_in_use in paca when running as LPAR

2019-07-31T05:25:01+00:00

commit 28d2a6e6684d9851905f379816d8a4d03587ed94 upstream. The ability to run nested guests under KVM means that a guest can also act as a hypervisor for it's own nested guest. Currently ppc_set_pmu_inuse() assumes that either FW_FEATURE_LPAR is set, indicating a guest environment, and so sets the pmcregs_in_use flag in the lppaca, or that it isn't set, indicating a hypervisor environment, and so sets the pmcregs_in_use flag in the paca. The pmcregs_in_use flag in the lppaca is used to communicate this information to a hypervisor and so must be set in a guest environment. The pmcregs_in_use flag in the paca is used by KVM code to determine whether the host state of the performance monitoring unit (PMU) must be saved and restored when running a guest. Thus when a guest also acts as a hypervisor it must set this bit in both places since it needs to ensure both that the real hypervisor saves it's PMU registers when it runs (requires pmcregs_in_use flag in lppaca), and that it saves it's own PMU registers when running a nested guest (requires pmcregs_in_use flag in paca). Modify ppc_set_pmu_inuse() so that the pmcregs_in_use bit is set in both the lppaca and the paca when a guest (LPAR) is running with the capability of running it's own guests (CONFIG_KVM_BOOK3S_HV_POSSIBLE). Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Suraj Jitindar Singh Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190703012022.15644-2-sjitindarsingh@gmail.com Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Fix oops on sigreturn on systems without TM

2019-07-31T05:25:01+00:00

commit f16d80b75a096c52354c6e0a574993f3b0dfbdfe upstream. On systems like P9 powernv where we have no TM (or P8 booted with ppc_tm=off), userspace can construct a signal context which still has the MSR TS bits set. The kernel tries to restore this context which results in the following crash: Unexpected TM Bad Thing exception at c0000000000022fc (msr 0x8000000102a03031) tm_scratch=800000020280f033 Oops: Unrecoverable exception, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 1636 Comm: sigfuz Not tainted 5.2.0-11043-g0a8ad0ffa4 #69 NIP: c0000000000022fc LR: 00007fffb2d67e48 CTR: 0000000000000000 REGS: c00000003fffbd70 TRAP: 0700 Not tainted (5.2.0-11045-g7142b497d8) MSR: 8000000102a03031 CR: 42004242 XER: 00000000 CFAR: c0000000000022e0 IRQMASK: 0 GPR00: 0000000000000072 00007fffb2b6e560 00007fffb2d87f00 0000000000000669 GPR04: 00007fffb2b6e728 0000000000000000 0000000000000000 00007fffb2b6f2a8 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000000000000 00007fffb2b76900 0000000000000000 0000000000000000 GPR16: 00007fffb2370000 00007fffb2d84390 00007fffea3a15ac 000001000a250420 GPR20: 00007fffb2b6f260 0000000010001770 0000000000000000 0000000000000000 GPR24: 00007fffb2d843a0 00007fffea3a14a0 0000000000010000 0000000000800000 GPR28: 00007fffea3a14d8 00000000003d0f00 0000000000000000 00007fffb2b6e728 NIP [c0000000000022fc] rfi_flush_fallback+0x7c/0x80 LR [00007fffb2d67e48] 0x7fffb2d67e48 Call Trace: Instruction dump: e96a0220 e96a02a8 e96a0330 e96a03b8 394a0400 4200ffdc 7d2903a6 e92d0c00 e94d0c08 e96d0c10 e82d0c18 7db242a6 <4c000024> 7db243a6 7db142a6 f82d0c18 The problem is the signal code assumes TM is enabled when CONFIG_PPC_TRANSACTIONAL_MEM is enabled. This may not be the case as with P9 powernv or if `ppc_tm=off` is used on P8. This means any local user can crash the system. Fix the problem by returning a bad stack frame to the user if they try to set the MSR TS bits with sigreturn() on systems where TM is not supported. Found with sigfuz kernel selftest on P9. This fixes CVE-2019-13648. Fixes: 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context") Cc: stable@vger.kernel.org # v3.9 Reported-by: Praveen Pandey Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190719050502.405-1-mikey@neuling.org Signed-off-by: Greg Kroah-Hartman

powerpc/mm: Limit rma_size to 1TB when running without HV mode

2019-07-31T05:25:01+00:00

commit da0ef93310e67ae6902efded60b6724dab27a5d1 upstream. The virtual real mode addressing (VRMA) mechanism is used when a partition is using HPT (Hash Page Table) translation and performs real mode accesses (MSR[IR|DR] = 0) in non-hypervisor mode. In this mode effective address bits 0:23 are treated as zero (i.e. the access is aliased to 0) and the access is performed using an implicit 1TB SLB entry. The size of the RMA (Real Memory Area) is communicated to the guest as the size of the first memory region in the device tree. And because of the mechanism described above can be expected to not exceed 1TB. In the event that the host erroneously represents the RMA as being larger than 1TB, guest accesses in real mode to memory addresses above 1TB will be aliased down to below 1TB. This means that a memory access performed in real mode may differ to one performed in virtual mode for the same memory address, which would likely have unintended consequences. To avoid this outcome have the guest explicitly limit the size of the RMA to the current maximum, which is 1TB. This means that even if the first memory block is larger than 1TB, only the first 1TB should be accessed in real mode. Fixes: c610d65c0ad0 ("powerpc/pseries: lift RTAS limit for hash") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Suraj Jitindar Singh Tested-by: Satheesh Rajendran Reviewed-by: David Gibson Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190710052018.14628-1-sjitindarsingh@gmail.com Signed-off-by: Greg Kroah-Hartman